<template>
  <div>
    <h1>App</h1>
    <h2>v2</h2>
    {{ count }} <button @click="count++">+</button>

    <h2>v3</h2>

    {{ age }} <button @click="say">say</button>
  </div>
</template>

<script>
export default {
  setup() {
    const age = 20;
    function say() {
      console.log(age);
    }
    return {
      age,
      say,
    };
  },
  data() {
    return {
      count: 100,
    };
  },
  methods: {
    add() {
      this.count++;
    }
  }
};
</script>